Do you get the room category you paid for?

I have read a few reviews in which it sounded like people booked and paid for a certain category of room and ended up having to spend a night or two in a lower category room until they could be put in the room they booked and paid for. How prevalent it this?
We spend a lot of time vacationing in Jamaica and have been to a lot of different resorts there. We are planning a short stay at CSA in June to sort of check it our for longer stays with a group of other couples. We have booked and paid for a Garden Verandah Suite for a short part of our vacation in Negril.
We will only be there 3 nights and would be pretty upset if we ended up in a lower room category for any of it and had to move in the middle of such a short stay. It would not be as big a concern if we were there for a week, but with just 3 nights it would be a bigger issue to us.
How likely is this to happen at the end of June? Is it a rare thing or a common problem? Is there anything within reason I can do to help keep this from happening? (I would hope that booking it and paying for it months in advance would enough, but in some trip reports it seems like it was not enough!)
Thanks!

This has never happened to us in seven previous stays. Although I've read about it happening, its normally during extra heavy travel times (during the winter months for us), or under exceptional circumstances (last year's travel ban in Mexico due to H1N1 scare, for example).

Don't sweat it... late June is part of Jamaica's and Negril's "low" season. There'll be plenty of folks at SweptAway, but I'd be surprised to hear that its very near to capacity.

We've been to CSA 4 times and CSS once, and every time have gotten the room category that we paid for every night of our stay. We have usually booked a higher end room and travel during January (high season). June is not peak season in the Caribbean, so I doubt that this will be an issue for you. Plus the Garden Verandah Suite is towards the lower end of the room-types. If anything, you might get upgraded rather than downgraded.

Do I know people who have not gotten the room category that they booked? Yes, but they have ALWAYS been compensated in some form for the inconvenience (room or spa credit), and it has never been for more than one night.